scholarly journals Identification of Harvest Maturity Indicators for ‘Hass’ Avocado Adaptable to Field Conditions

2018 ◽  
Vol 28 (6) ◽  
pp. 815-821 ◽  
Author(s):  
Pablo Rodriguez ◽  
Juan Camilo Henao ◽  
Guillermo Correa ◽  
Ana Aristizabal
Keyword(s):  
Fruit Development ◽  
Development Time ◽  
Principal Component ◽  
The United States ◽  
International Markets ◽  
Fruit Color ◽  
Persea Americana ◽  
Market Requirements ◽  
Hass Avocado ◽  
Harvest Maturity

‘Hass’ avocado (Persea americana) is a fruit in high demand in international markets, and Colombia is expanding its export to the United States. Avocado quality and shelf life are related to its harvest time. However, there is not enough information on harvest indicators in Colombia that allow producers to adequately harvest fruit to comply with market requirements. Therefore, the aim of this study was to estimate maturity indicators during two harvest periods. We harvested fruit between the years 2016 and 2017 in eight farms distributed in three regions of the Department of Antioquia, Colombia, and selected those in the postanthesis stages. We assessed variables such as fruit color, weight, dimensions, oil content (OC), and dry matter (DM). The results were analyzed using simple and multiple regressions as well as by principal component analysis (PCA). The results showed a high linear relation between DM and OC (R2 ≥ 78.88) and a significant relation between OC, rainfall, fruit development time, and environmental temperature. Nondestructive indicators that allow the establishment of DM in the field (R2 ≥ 73.57) varied according to the region and included fruit color (L*, b*), volume (P ≤ 0.05), and fruit development time. These indicators could reduce maturity heterogeneity during the harvest period.

scholarly journals Classification of Hass avocado (persea americana mill) in terms of its ripening via hyperspectral images

TecnoLógicas ◽  
2019 ◽  
Vol 22 (45) ◽  
pp. 109-128 ◽  
Author(s):  
Jhon Pinto ◽  
Hoover Rueda-Chacón ◽  
Henry Arguello
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Agricultural Sector ◽  
Low Cost ◽  
Color Space ◽  
Principal Component ◽  
Persea Americana ◽  
Hyperspectral Images ◽  
Non Invasive ◽  
Hass Avocado

The use of non-invasive and low-cost methodologies allows the monitoring of fruit ripening and quality control, without affecting the product under study. In particular, the Hass avocado is of high importance for the agricultural sector in Colombia because the country is strongly promoting its export, which has generated an expansion in the number of acres cultivated with this fruit. Therefore, this paper aims to study and analyze the ripening state of Hass avocados through non-invasive hyperspectral images, using principal component analysis (PCA) along with spectral vegetation indices, such as the normalized difference vegetation index (NDVI), ratio vegetation index (RVI), photochemical reflectance index (PRI), colorimetry analysis in the CIE L*a*b* color space, and color index triangular greenness index (TGI). In particular, this work conducts a quantitative analysis of the ripening process of a population of 7 Hass avocados over 10 days. The avocados under study were classified into three categories: unripe, close-to-ripe, and ripe. The obtained results show that it is possible to characterize the ripening state of avocados through hyperspectral images using a non-invasive acquisition system. Further, it is possible to know the post-harvest ripening state of the avocado at any given day.

scholarly journals An Econometric Demand Model for Florida Green-skin Avocados

2015 ◽  
Vol 25 (3) ◽  
pp. 405-411 ◽  
Author(s):  
Edward A. Evans ◽  
Fredy H. Ballen
Keyword(s):  
The United States ◽  
Persea Americana ◽  
Demand Model ◽  
Long Run ◽  
Recent Outbreak ◽  
Production Area ◽  
Price Flexibility ◽  
The Mean ◽  
Hass Avocado ◽  
The Impact

This article develops an inverse demand model for Florida green-skin avocados (Persea americana). Information from the model is used to assess the likely impact on growers’ prices resulting from a reduction in the supply of Florida green-skin avocados due to a recent outbreak of a deadly fungus in the Florida commercial avocado production area. Consideration is also given to the increased supply of green-skin avocados imported to the United States from the Dominican Republic (DR), as well as the increased availability of ‘Hass’ avocado in the U.S. market. The estimated own price flexibility of –0.551 evaluated at the mean suggests that Florida avocado prices are not very responsive to changes in quantity supplied. A reduction in the quantity supplied is likely to bring about a less than proportionate rise in the price. Moreover, any noticeable rise in prices due to the impact of the disease is likely to be short lived and may be insufficient to cover additional grove management costs. In the longer run, prices are expected to revert closer to their long-run trend (or decrease) as a result of increased shipments from the DR, and further increases in the availability of ‘Hass’ avocados.

scholarly journals Associations between Google Search Trends for Symptoms and COVID-19 Confirmed and Death Cases in the United States

2021 ◽  
Vol 18 (9) ◽  
pp. 4560
Author(s):  
Mostafa Abbas ◽  
Thomas B. Morland ◽  
Eric S. Hall ◽  
Yasser EL-Manzalawy
Keyword(s):  
Functional Data ◽  
Time Series Data ◽  
Principal Component ◽  
State Level ◽  
The United States ◽  
Functional Principal Component Analysis ◽  
Series Data ◽  
Dynamic Correlation ◽  
The Us ◽  
Google Search

We utilize functional data analysis techniques to investigate patterns of COVID-19 positivity and mortality in the US and their associations with Google search trends for COVID-19-related symptoms. Specifically, we represent state-level time series data for COVID-19 and Google search trends for symptoms as smoothed functional curves. Given these functional data, we explore the modes of variation in the data using functional principal component analysis (FPCA). We also apply functional clustering analysis to identify patterns of COVID-19 confirmed case and death trajectories across the US. Moreover, we quantify the associations between Google COVID-19 search trends for symptoms and COVID-19 confirmed case and death trajectories using dynamic correlation. Finally, we examine the dynamics of correlations for the top nine Google search trends of symptoms commonly associated with COVID-19 confirmed case and death trajectories. Our results reveal and characterize distinct patterns for COVID-19 spread and mortality across the US. The dynamics of these correlations suggest the feasibility of using Google queries to forecast COVID-19 cases and mortality for up to three weeks in advance. Our results and analysis framework set the stage for the development of predictive models for forecasting COVID-19 confirmed cases and deaths using historical data and Google search trends for nine symptoms associated with both outcomes.

scholarly journals Dietary patterns related to total mortality and cancer mortality in the United States

2021 ◽  
Author(s):  
Marcela R. Entwistle ◽  
Donald Schweizer ◽  
Ricardo Cisneros
Keyword(s):  
United States ◽  
Dietary Patterns ◽  
Cancer Mortality ◽  
Cox Regression ◽  
Total Mortality ◽  
Principal Component ◽  
The United States ◽  
Red Meat ◽  
Increased Risk ◽  
All Cause Mortality

Abstract Purpose This study investigated the association between dietary patterns, total mortality, and cancer mortality in the United States. Methods We identified the four major dietary patterns at baseline from 13,466 participants of the NHANES III cohort using principal component analysis (PCA). Dietary patterns were categorized into ‘prudent’ (fruits and vegetables), ‘western’ (red meat, sweets, pastries, oils), ‘traditional’ (red meat, legumes, potatoes, bread), and ‘fish and alcohol’. We estimated hazard ratios for total mortality, and cancer mortality using Cox regression models. Results A total of 4,963 deaths were documented after a mean follow-up of 19.59 years. Higher adherence to the ‘prudent’ pattern was associated with the lowest risk of total mortality (5th vs. 1st quintile HR 0.90, 95% CI 0.82–0.98), with evidence that all-cause mortality decreased as consumption of the pattern increased. No evidence was found that the ‘prudent’ pattern reduced cancer mortality. The ‘western’ and the ‘traditional’ patterns were associated with up to 22% and 16% increased risk for total mortality (5th vs. 1st quintile HR 1.22, 95% CI 1.11–1.34; and 5th vs. 1st quintile HR 1.16, 95% CI 1.06–1.27, respectively), and up to 33% and 15% increased risk for cancer mortality (5th vs. 1st quintile HR 1.33, 95% CI 1.10–1.62; and 5th vs. 1st quintile HR 1.15, 95% CI 1.06–1.24, respectively). The associations between adherence to the ‘fish and alcohol’ pattern and total mortality, and cancer mortality were not statistically significant. Conclusion Higher adherence to the ‘prudent’ diet decreased the risk of all-cause mortality but did not affect cancer mortality. Greater adherence to the ‘western’ and ‘traditional’ diet increased the risk of total mortality and mortality due to cancer.

scholarly journals Laurel Wilt: Current and Potential Impacts and Possibilities for Prevention and Management

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 181
Author(s):  
Rabiu O. Olatinwo ◽  
Stephen W. Fraedrich ◽  
Albert E. Mayfield
Keyword(s):  
United States ◽  
Tree Mortality ◽  
The United States ◽  
Persea Americana ◽  
Laurel Wilt ◽  
Important Species ◽  
Invasive Insects ◽  
Raffaelea Lauricola ◽  
Redbay Ambrosia Beetle ◽  
The Impact

In recent years, outbreaks of nonnative invasive insects and pathogens have caused significant levels of tree mortality and disturbance in various forest ecosystems throughout the United States. Laurel wilt, caused by the pathogen Raffaelea lauricola (T.C. Harr., Fraedrich and Aghayeva) and the primary vector, the redbay ambrosia beetle (Xyleborus glabratus Eichhoff), is a nonnative pest-disease complex first reported in the southeastern United States in 2002. Since then, it has spread across eleven southeastern states to date, killing hundreds of millions of trees in the plant family Lauraceae. Here, we examine the impacts of laurel wilt on selected vulnerable Lauraceae in the United States and discuss management methods for limiting geographic expansion and reducing impact. Although about 13 species belonging to the Lauraceae are indigenous to the United States, the highly susceptible members of the family to laurel wilt are the large tree species including redbay (Persea borbonia (L.) Spreng) and sassafras (Sassafras albidum (Nutt.) Nees), with a significant economic impact on the commercial production of avocado (Persea americana Mill.), an important species native to Central America grown in the United States. Preventing new introductions and mitigating the impact of previously introduced nonnative species are critically important to decelerate losses of forest habitat, genetic diversity, and overall ecosystem value.

Note. Effect of Storage Temperature on the Shelf Life of Hass Avocado (Persea Americana)

2004 ◽  
Vol 10 (2) ◽  
pp. 73-77 ◽  
Author(s):  
K. Perez ◽  
J. Mercado ◽  
H. Soto-Valdez
Keyword(s):  
Weight Loss ◽  
Shelf Life ◽  
Respiration Rate ◽  
Ethylene Production ◽  
Storage Temperature ◽  
Persea Americana ◽  
Co2 Production ◽  
Hass Avocado ◽  
Storage Temperatures

The effect of storage temperature on the shelf life, weight loss, respiration rate and ethylene production of Hass avocado (Persea americana Mill) was studied. Two batches of green mature avocado fruits, classified as ‘‘super extra’’ were stored at 10 and 20 C (first batch) and at 7 and 25 C (second batch). The avocado shelf lives were 22, 8, 32 and 6 days at 10, 20, 7 and 25 C, respectively. Based on the data of the first assay Q10 was calculated as 2.75, with this value the predicted shelf life at 7 and 25 C were 29.8 and 4.8 days, respectively. That meant shelf life was underestimated 7 and 20% at 7 and 25 C, respectively. Weight loss was linear at both the storage temperatures, it was 4.3% in fruits at 20 C for 8 days and 3.0% at 10 C for 22 days. The maximum CO2 production at 20 C was reached during the second day of storage, while at 10 C it was reached at the 17th day (176.17 15.98 and 74.73 7.32 mL/kg h, respectively). The maximum ethylene production at 20 C was reached the second day of storage, and at 10 C the 6th day (239.06 54.55 and 28.00 8.12 mL/kg h, respectively).

Alstom Gas Turbine Technology Overview: Status 2014

2015 ◽  
Author(s):  
Wolfgang Kappis ◽  
Stefan Florjancic ◽  
Uwe Ruedel
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
New Technologies ◽  
The United States ◽  
Heavy Duty ◽  
Fuel Flexibility ◽  
Market Requirements ◽  
Base Load ◽  
Very High

Market requirements for the heavy duty gas turbine power generation business have significantly changed over the last few years. With high gas prices in former times, all users have been mainly focusing on efficiency in addition to overall life cycle costs. Today individual countries see different requirements, which is easily explainable picking three typical trends. In the United States, with the exploitation of shale gas, gas prices are at a very low level. Hence, many gas turbines are used as base load engines, i.e. nearly constant loads for extended times. For these engines reliability is of main importance and efficiency somewhat less. In Japan gas prices are extremely high, and therefore the need for efficiency is significantly higher. Due to the challenge to partly replace nuclear plants, these engines as well are mainly intended for base load operation. In Europe, with the mid and long term carbon reduction strategy, heavy duty gas turbines is mainly used to compensate for intermittent renewable power generation. As a consequence, very high cyclic operation including fast and reliable start-up, very high loading gradients, including frequency response, and extended minimum and maximum operating ranges are required. Additionally, there are other features that are frequently requested. Fuel flexibility is a major demand, reaching from fuels of lower purity, i.e. with higher carbon (C2+), content up to possible combustion of gases generated by electrolysis (H2). Lifecycle optimization, as another important request, relies on new technologies for reconditioning, lifetime monitoring, and improved lifetime prediction methods. Out of Alstom’s recent research and development activities the following items are specifically addressed in this paper. Thermodynamic engine modelling and associated tasks are discussed, as well as the improvement and introduction of new operating concepts. Furthermore extended applications of design methodologies are shown. An additional focus is set ono improve emission behaviour understanding and increased fuel flexibility. Finally, some applications of the new technologies in Alstom products are given, indicating the focus on market requirements and customer care.

scholarly journals Characterization and Pathogenicity of Botryosphaeriaceae Species Obtained from Avocado Trees with Branch Canker and Dieback and from Avocado Fruit with Stem End Rot in Chile

Plant Disease ◽  
2019 ◽  
Vol 103 (5) ◽  
pp. 996-1005 ◽  
Author(s):  
Ana L. Valencia ◽  
Pilar M. Gil ◽  
Bernardo A. Latorre ◽  
I. Marlene Rosales
Keyword(s):  
Vascular System ◽  
Persea Americana ◽  
Effective Control ◽  
Future Research ◽  
Severe Drought ◽  
Internal Transcribed Spacer Region ◽  
Avocado Fruit ◽  
Hass Avocado ◽  
Botryosphaeriaceae Species ◽  
Branch Canker

Several species of the Botryosphaeriaceae family have been associated with branch canker, dieback, and stem end rot in avocado (Persea americana Mill.). In Chile, the incidence of diseases affecting the avocado tree increased from 2011 to 2016, which coincided with a severe drought that affected avocado production. Moreover, distant countries importing avocados from Chile also reported an increase of stem end rot of ripe avocados. Therefore, the aims of this study were to identify the pathogen species associated with branch canker, dieback, and stem end rot of avocado in Chile and to study their pathogenicity. This study was conducted between 2015 and 2016 in ‘Hass’ avocado orchards located in the main avocado-producing regions in Chile. A diverse collection of fungal species was recovered from both necrotic woody tissue and necrotic tissue on harvested ripe fruit. On the basis of morphology and phylogenetic analyses of the internal transcribed spacer region (ITS1-5.8S-ITS2) and the translation elongation factor 1-α (TEF1-α) gene, eight species in the Botryosphaeriaceae family were identified: Diplodia mutila, D. pseudoseriata, D. seriata, Dothiorella iberica, Lasiodiplodia theobromae, Neofusicoccum australe, N. nonquaesitum, and N. parvum. For each of these species, pathogenicity studies were conducted on 1-year-old healthy Hass avocado plants. All isolates produced brown gum exudate and caused necrosis in the vascular system 3 weeks after inoculation. N. nonquaesitum, N. parvum, and D. pseudoseriata were the most virulent species. Necrotic lesions and cavities with white mycelia near the peduncle union were observed on Hass avocado fruit inoculated postharvest. L. theobromae, N. australe, and N. parvum were significantly more virulent than the other tested species in the Botryosphaeriaceae family. This study identified and characterized the pathogenicity of Botryosphaeriaceae species in Chile, which will prove useful to future research on these pathogens directed at establishing effective control strategies in avocado.

Sign in / Sign up

Export Citation Format

Share Document